Identification of Tumorigenic and Prognostic Biomarkers in Colorectal Cancer Based on microRNA Expression Profiles

KLF4 suppresses the proliferation and metastasis of NSCLC cells via inhibition of MSI2 and regulation of the JAK/STAT3 signaling pathway

•

KLF4 is downregulated, while MSI2 is upregulated in NSCLC tissues.

•

Overexpression of KLF4 suppresses NSCLC cell migration and invasion.

•

Knockdown of MSI2 suppresses the migration and invasion of NSCLC cells.

•

KLF4 inhibits the transcription of MSI2 in NSCLC cells.

•

KLF4 suppressed the invasion and migration of NSCLC cells via inhibition of JAK2/STAT3 signalling pathway.

Background

Non-small cell lung cancer (NSCLC) remains an aggresive tumor with poor survival rates. Krüppel-like factor 4 (KLF4) is known to be involved in progression of NSCLC; however, the detailed mechanism by which KLF4 regulates the progression of NSCLC remains unclear.

Methods

In order to investigate the function of KLF4 in NSCLC, cell proliferation was measured by MTT and colony formation assays. The migration and invasion of NSCLC cells were detected via wound healing and Transwell assays, respectively. Then, the interaction between KLF4 and MSI2 was confirmed using a dual-luciferase reporter assay, and the mechanism by which KLF4 regulates the tumorigenesis of NSCLC was assessed by RT-qPCR and Western blotting.

Results

The results showed that KLF4 was downregulated, while MSI2 was upregulated in NSCLC. Additionally, KLF4 could inhibit transcription of MSI2, and overexpression of KLF4 or knockdown of MSI2 could inhibit the proliferation, migration and invasion of NSCLC cells. Moreover, KLF4 could inhibit JAK2/STAT3 signalling pathway.

Conclusions

In conclusion, KLF4 significantly inhibited the proliferation, invasion and migration of NSCLC cells via inactivation of MSI2/JAK2/STAT3 signalling pathway. Thereby, our finding might shed new lights on exploring the new strategies against NSCLC.

MicroRNAs as important contributors in the pathogenesis of colorectal cancer

Colorectal cancer (CRC) is the third most fatal and fourth most frequently diagnosed neoplasm in the world. Numerous non-coding RNAs have been shown to contribute in the development of CRC. MicroRNAs (miRNAs) are among the mostly assessed non-coding RNAs in CRC. These transcripts influence expression and activity of TGF-β, Wnt/β-catenin, MAPK, PI3K/AKT and other CRC-related pathways. In the context of CRC, miRNAs interact with long non-coding RNAs to influence CRC course. Stool and serum levels of miRNAs have been used to distinguish CRC patients from healthy controls, indicating diagnostic roles of these transcripts in CRC. Therapeutic application of miRNAs in CRC has been assessed in animal models, yet has not been verified in clinical settings. In the current review, we have provided a recent update on the role of miRNAs in CRC development as well as diagnostic and prognostic approaches.

Advances in poly(rC)-binding protein 2: Structure, molecular function, and roles in cancer

Poly(rC)-binding protein 2 (PCBP2) is an RNA-binding protein that is characterized by its ability to interact with poly(C) with high affinity in a sequence-specific manner. PCBP2 contains three K homology domains, which are consensus RNA-binding domains that play a role in recognizing and combining with RNA and DNA. The specific structure and localization of PCBP2 lay the foundation for its multiple roles in transcriptional, posttranscriptional, and translational processes, even in iron metabolism. Numerous studies have indicated that PCBP2 expression is increased in many cancer types. PCBP2 is considered as an oncogene that promotes tumorigenesis, development of cancer cells, and metastasis. Here, we summarized the current evidence regarding PCBP2 in the proliferation, migration, invasion of cancer cells, and drug resistance, aiming to clarify the molecular mechanisms of PCBP2 in cancer. Results from this review suggest that an in-depth study of PCBP2 in cancer may provide novel biomarkers for prognostic or therapeutic purposes.

Panel of serum miRNAs as potential non-invasive biomarkers for pancreatic ductal adenocarcinoma

Early-stage diagnosis of pancreatic ductal adenocarcinoma (PDAC) is difficult due to non-specific symptoms. Circulating miRNAs in body fluids have been emerging as potential non-invasive biomarkers for diagnosis of many cancers. Thus, this study aimed to assess a panel of miRNAs for their ability to differentiate PDAC from chronic pancreatitis (CP), a benign inflammatory condition of the pancreas. Next-generation sequencing was performed to identify miRNAs present in 60 FFPE tissue samples (27 PDAC, 23 CP and 10 normal pancreatic tissues). Four up-regulated miRNAs (miR-215-5p, miR-122-5p, miR-192-5p, and miR-181a-2-3p) and four down-regulated miRNAs (miR-30b-5p, miR-216b-5p, miR-320b, and miR-214-5p) in PDAC compared to CP were selected based on next-generation sequencing results. The levels of these 8 differentially expressed miRNAs were measured by qRT-PCR in 125 serum samples (50 PDAC, 50 CP, and 25 healthy controls (HC)). The results showed significant upregulation of miR-215-5p, miR-122-5p, and miR-192-5p in PDAC serum samples. In contrast, levels of miR-30b-5p and miR-320b were significantly lower in PDAC as compared to CP and HC. ROC analysis showed that these 5 miRNAs can distinguish PDAC from both CP and HC. Hence, this panel can serve as a non-invasive biomarker for the early detection of PDAC.